1. Field of the Invention
The present invention relates to a printing apparatus which prints on a continuous sheet and cuts before discharging.
2. Description of the Related Art
With a printing apparatus capable of continuous printing of a great number of sheets, sheet conveying jamming (hereinafter simply referred to as “jamming”) may occur within a sorter where sheets are sorted to multiple discharge trays. Once jamming occurs, all or part of various processing units upstream of the discharge trays have to be stopped, which has great negative impact, such as subsequent jobs being stopped, and so forth.
The printing apparatus disclosed in Japanese Patent Laid-Open No. 11-208984 has a function of sorting sheets to multiple discharge trays (discharge bins) in a sorter. In the event that jamming occurs in the sorter while performing consecutive printing, a sheet conveyance path is switched over, so as to discharge sheets to a tray other than the discharge tray which has become unavailable for use. Accordingly, even if jamming does occur, the probability of subsequent jobs stopping is reduced.
With the device in Japanese Patent Laid-Open No. 11-208984, there are cases that some sort of trouble occurs at the discharge unit at the time of performing continuous printing, and printed articles cannot be accepted any more. For example, in the event that jamming occurs at the sorter, only discharge trays upstream from the position where the jamming has occurred can be used. The further upstream within the sorter the position where the jamming has occurred is, the greater the restriction is on the number of sheets which can be accepted, since the number of discharge trays which are available is reduced. In the event that the discharge tray most upstream becomes unavailable, acceptance of sheets becomes completely unavailable.
As for another example of trouble, even if no jamming occurs, if the device is run for a long time with no user attending to it, and accordingly the printed articles are not removed from the discharge trays for a long period of time, all discharge trays will become full of printed articles. If such a state continues, there will be no destination available for the printed articles, so the device has to be shut down immediately.